Genius billionaire inventor, industrialist and CEO of Stark Industries Tony Stark was fatally wounded in a war zone in Afghanistan shortly before being kidnapped by terrorists. Stark built an armored suit to escape captivity, which doubled as a device to keep his heart beating keeping him alive. Once he returned to the United States, Stark reinvented himself as the armor-clad superhero Iron Man.
In times when Tony Stark was indisposed, other men have carried on the legacy of Iron Man. Twice did Tony's best friend Jim Rhodes, and the duty has fallen into the hands of the reformed villain Victor von Doom. Most recently, the role has been usurped by Tony's adopted brother, Arno Stark.
(Currently War Machine)
Victor von Doom
(Currently Doctor Doom)
(Currently Iron Man)